Within the field of cutting tools used in milling operations, there are some examples of triangular-shaped indexable cutting inserts having recessed side surfaces, removably retained in an insert receiving pocket of a cutting body.
CN 103506680 discloses a triangular shaped indexable cutting insert having opposing upper and lower end surfaces with a peripheral surface extending therebetween, the peripheral surface including three side surfaces and three corner surfaces, each corner surface intersecting an upper end surface to form a curved upper cutting edge, and each side surface having a recessed side surface.
US 2016/0107248 discloses a triangular shaped indexable cutting insert having opposing upper and lower end surfaces with a peripheral surface extending therebetween, the peripheral surface including three side surfaces and three corner surfaces, each corner surface intersecting an upper end surface to form an upper cutting edge. Each upper cutting edge includes a radiused component having a first end and a second end and first and second components at the first and the second ends of the radiused component, respectively, the first and second components being less curved than the radiused component. The lower end surface includes three radially extending mounting grooves, and each side surface includes at least one substantially V-shaped valley formed by first and second support surfaces.
US 2010/0329800 discloses a double-sided indexable cutting insert having three heads spaced apart by an intermediate part, each head including a front portion, both sides of which have two essentially straight cutting edges converging at a nose edge, and a rear portion which has two side contact surfaces. The intermediate part has three ‘recessed’ intermediate surfaces, which in a top view or a bottom view of the cutting insert define an imaginary triangle, none of the imaginary sides of which traverse any of the cutting edges.